Syringe having a collapsible plunger rod

ABSTRACT

A syringe assembly includes a syringe barrel having an exterior surface, an inside surface defining a chamber, an open proximal end, a distal end, and an outlet disposed adjacent the distal end in fluid communication with the chamber; and a plunger assembly disposed at least partially within the syringe barrel. The plunger assembly includes an elongated plunger rod and a plunger head. The elongated plunger rod is associated with the plunger head to move the plunger head within the chamber of the syringe barrel through an injection cycle. The plunger rod is adapted to move from a collapsed position extending alongside the exterior surface of the syringe barrel to an extended position engaging the plunger head to move the plunger head through the injection cycle.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.12/859,823 entitled “Syringe Having a Collapsible Plunger Rod” filedAug. 20, 2010, which claims benefit of U.S. Provisional PatentApplication Ser. Nos. 61/235,869 entitled “Syringe Having a CollapsiblePlunger Rod” filed Aug. 21, 2009; and 61/235,848 entitled “MagnifyingCollapsed Plunger Rod” filed Aug. 21, 2009, the disclosures of each ofwhich are hereby incorporated by reference in their entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a hypodermic syringe that has a compactsize, and includes a plunger mechanism positioned externally adjacentthe syringe when filled.

2. Description of Related Art

Syringe assemblies, and in particular hypodermic syringes, are wellknown in the medical field for dispensing fluids, such as medication. Aconventional syringe typically includes a syringe barrel with an openingat one end and a plunger mechanism disposed through the other end. Theplunger typically includes a plunger rod extending through the barrel,with a plunger head or stopper at the end of the plunger rod within thebarrel and with a finger flange at the other end of the plunger rodextending out of the barrel. In use, the plunger rod is retractedthrough the syringe barrel to aspirate or fill the syringe barrel with afluid, such as a medication, with the plunger rod extending out from therear end of the syringe barrel. For delivery of the medication to apatient, the opening of the syringe barrel is adapted for fluidcommunication with a patient, such as through a hypodermic needle fittedat the front end of the syringe barrel or through a luer-type fittingextending from the front end of the syringe barrel for attachment with afluid line of a patient. Upon depressing of the plunger rod, the plungerrod and stopper travel through the syringe barrel, thereby forcing thecontents of the syringe out through the opening at the front end fordelivery to the patient. Such an operation is well known in the medicalfield, and medical practitioners have become well accustomed to the useof such common fluid delivery procedures through standard syringes.

Conventional syringes are well known to be used in connection with avial of a medication, where the user draws the fluid into the syringeimmediately prior to injection and delivery of the fluid to the patient.Oftentimes, hypodermic syringes may be packaged as “pre-filled” devices,wherein the syringe is pre-filled with medication prior to beingpackaged and delivered to the end user. In this manner, there is no needfor the user to fill the device prior to injection, thereby saving timefor the end user and maintaining consistent volumes for delivery.

Packaging of such pre-filled syringes, however, tends to be bulky. Apre-filled syringe is typically packaged with the opening at the frontend of the barrel including a separate cap thereover and with theplunger rod retracted out of the back end of the syringe barrel, withthe fluid pre-filled within the syringe barrel. Such packaging createsan elongated package that can be awkward for shipping and storage.

Pre-filled syringes and pre-filled metered dose syringes are oftenfilled with narcotics or other drugs at a production facility, packaged,and then shipped to a medical facility. Once at the facility, thesesyringes are often placed in controlled storage and/or locked cabinetsto reduce theft of the syringes themselves and/or through of thecontents of these syringes. The space within these controlled storagelocations is often limited, thus there is a need for a syringe assemblythat has a smaller packing footprint, to reduce the storage spacerequired for containing the syringe. It is also desirable to producesyringes that are uniform in terms of an outer surface shape to allowfor stacking of these syringes within the storage cabinet.

Typical pre-filled hypodermic syringes have elongated plunger rodsextending from beyond the proximal end of a syringe barrel to move thestopper through an injection cycle within the syringe barrel by linearactuation of the elongated plunger rod. This arrangement increases thelength of the packaged syringe assembly, which increases costsassociated with packaging the pre-filled syringe and takes up additionalstorage space.

SUMMARY OF THE INVENTION

Accordingly, there is a general need for a hypodermic syringe that has areduced length and width when the syringe barrel is filled with a liquidmedication prior to injection.

According to an embodiment of the present invention, a syringe assemblyis provided. The syringe assembly includes: a syringe barrel having anexterior surface, an inside surface defining a chamber, an open proximalend, a distal end, and an outlet disposed adjacent the distal end influid communication with the chamber; and a plunger assembly disposed atleast partially within the syringe barrel. The plunger assembly includesan elongated plunger rod and a plunger head, the elongated plunger rodbeing associated with the plunger head to move the plunger head withinthe chamber of the syringe barrel through an injection cycle. Theplunger rod is adapted to move from a collapsed position extendingalongside the exterior surface of the syringe barrel to an extendedposition engaging the plunger head to move the plunger head through theinjection cycle.

The plunger rod may be slidably disposed on the syringe barrel. Theplunger rod includes a handle portion and at least two flexible legsextending distally from the handle portions. The at least two flexiblelegs are slidable with respect to the syringe barrel and the plungerhead so that the plunger rod is movable from the collapsed positionwherein the flexible legs extend alongside and wrap over the exteriorsurface of the syringe barrel and the extended position wherein theflexible legs engage the plunger head to move the plunger head throughthe injection cycle. Each of the at least two flexible legs includes ahook formed at a distal end of the flexible leg, the hook being adaptedto engage the plunger head. The handle portion is disposed proximate tothe proximal end of the syringe barrel in the collapsed position.

The syringe barrel may further include an outwardly extending flangedisposed at the open proximal end of the syringe barrel, the outwardlyextending flange having at least two apertures defined therein. The atleast two flexible legs of the plunger rod extend through the at leasttwo apertures in the outwardly extending flange in the collapsedposition.

The syringe barrel may, alternatively, further include at least twoslots extending between the inside surface and the exterior surface ofthe syringe barrel. The at least two flexible legs of the plunger rodextend through the at least two slots in the syringe barrel in thecollapsed position.

The plunger head includes a stopper having a proximal surface, a distalsurface, and a peripheral surface extending between the proximal surfaceand the distal surface, the peripheral surface including at least onesealing surface for sealingly engaging the inside surface of the syringebarrel. The plunger head further includes a stopper adapter disposed onthe distal surface of the stopper, the stopper adapter being adapted toengage the plunger rod during the injection cycle. The stopper adapteris at least partially hollow and includes a sidewall having at least twoslots defined therein. The plunger rod includes a handle portion and atleast two flexible legs extending distally from the handle portions, theat least two flexible legs being slidable with respect to the syringebarrel and the plunger head so that the plunger rod is movable from acollapsed position wherein the flexible legs extend through the at leasttwo slots in the sidewall of the stopper adapter alongside and adjacentto the exterior surface of the syringe barrel and an extended positionwherein distal ends of the flexible legs engage the slots in the stopperadapter to move the plunger head through the injection cycle.

The exterior surface of the syringe barrel may include a recessed gripportion defined therein. The recessed grip portion may include anover-molded gripping surface and/or a plurality of gripping dimples.

According to an alternative embodiment of the present invention, theplunger rod extends substantially parallel with the exterior surface ofthe syringe barrel in the collapsed position and extends substantiallyin line with a longitudinal axis of the syringe barrel in the extendedposition. The plunger rod includes a first end and a second end, and anattachment member located at the second end. The attachment member onthe plunger rod secures the plunger rod to the plunger head in theextended position. The plunger head includes a stopper having a proximalsurface, a distal surface, and a peripheral surface extending betweenthe proximal surface and the distal surface, the peripheral surfaceincluding at least one sealing surface for sealingly engaging the insidesurface of the syringe barrel. The plunger head further includes astopper adapter disposed on the distal surface of the stopper, thestopper adapter being adapted to engage the plunger rod during theinjection cycle.

The syringe assembly according to the alternative embodiment furtherincludes a flange located at the proximal end of the syringe barrel, theflange including an opening in alignment with an opening in the stopperadapter through which the plunger rod extends. Movement of the plungerrod from the collapsed position to the extended position includespivoting the second end of the plunger rod in a radial direction withrespect to the syringe barrel and then applying a proximal force to theplunger rod to axially slide the plunger rod through the openings in theflange and the stopper adapter and secure the attachment member on thesecond end of the plunger rod with the stopper adapter. The plunger rodincludes a thumb press member located at said first end of said plungerrod and is located above the proximal end of the syringe barrel.

According to still another embodiment of the present invention, a methodof actuating a syringe assembly is provided. The method includes thestep of providing a syringe assembly that includes a syringe barrelhaving an exterior surface, an inside surface defining a chamber, anopen proximal end, a distal end, and an outlet disposed adjacent thedistal end in fluid communication with the chamber; and a plungerassembly disposed at least partially within the syringe barrel, theplunger assembly including an elongated plunger rod and a plunger head,the plunger rod including a handle portion and at least two flexiblelegs extending distally from the handle portion and the plunger headincluding a stopper and a stopper adapter disposed on a distal surfaceof the stopper. Each of the at least two flexible legs includes a hookformed at a distal end of the flexible leg. The syringe barrel furtherincludes at least two openings defined therein. The plunger rod isdisposed in a collapsed position relative to the syringe barrel and theplunger head with the at least two flexible legs extending through theat least two openings in the syringe barrel and alongside and adjacentto the exterior surface of the syringe barrel and the handle portionpositioned proximate to the proximal end of the syringe barrel. Theplunger rod is then withdrawn from the collapsed position such that thehooks of the at least two flexible legs pass through the at least twoopenings in the syringe barrel. The stopper adapter is then engaged withthe hooks of the at least two flexible legs to lock the plunger rod intoengagement with the plunger head. The plunger assembly is then advancedwithin the chamber of the syringe barrel so that the stopper slideswithin the chamber with respect to the syringe barrel in a distaldirection. The syringe barrel further includes an outwardly extendingflange disposed at the open proximal end of the syringe barrel and theat least two openings are apertures defined in the outwardly extendingflange or, alternatively, at least two openings are slots extendingbetween the inside surface and the exterior surface of the syringebarrel.

Further details and advantages of the invention will become clear uponreading the following detailed description in conjunction with theaccompanying drawing figures, wherein like parts are designated withlike reference numerals throughout.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a syringe assembly according to anembodiment of the present invention.

FIG. 2 is a perspective view of a syringe assembly according to afurther embodiment of the present invention.

FIG. 3 is a partial side view of the syringe assembly shown in FIG. 2.

FIG. 4 is partial cross-sectional view of a syringe barrel and outertube of a syringe assembly according to yet another embodiment of thepresent invention.

FIGS. 5A-5F are perspective views of the syringe assembly according tothe present invention shown in successive views during an activation andinjection cycle, with FIG. 5A showing the plunger mechanism in a firststate prior to activation; FIG. 5B showing the plunger mechanism duringinitial retraction; FIG. 5C showing the plunger mechanism in a fullyretracted state; FIG. 5D showing the plunger mechanism just prior to theinjection cycle; FIG. 5E showing the plunger mechanism during theinjection cycle; and FIG. 5F showing the plunger mechanism aftercompletion of the injection cycle with the plunger head bottomed out.

FIG. 6 is a perspective view comparing a conventional syringe to asyringe assembly in accordance with the present invention.

FIG. 7 is a side elevation view of a syringe assembly according toanother embodiment of the present invention, including the collapsedplunger rod of the present invention in a pre-use position.

FIG. 8A is a perspective view of the syringe assembly of FIG. 7, havinga plunger rod pivoted away from the syringe barrel during transition ofthe syringe from the initial position to the ready-to-use position.

FIG. 8B is a partial perspective view of the syringe assembly of FIG. 8Ashowing engagement of the plunger rod during transition of the syringefrom the initial position to the ready-to-use position.

FIG. 8C is a partial perspective view of the syringe assembly of FIG. 8Ashowing engagement of the plunger rod during further transition of thesyringe from the initial position to the ready-to-use position.

FIG. 8D is a partial front cross-sectional view of the syringe assemblyof FIG. 8A in the ready-to-use position.

FIG. 9A is a front cross-sectional view of the syringe assembly of FIG.8A in the ready-to-use position.

FIG. 9B is a side view of the syringe assembly of FIG. 8A.

FIG. 9C is a perspective view of the syringe assembly of FIG. 8A.

FIG. 10A is a perspective view of the syringe assembly according toanother embodiment of the present invention, having a plunger rod in aninitial position.

FIG. 10B is a perspective view of the syringe assembly of FIG. 10Ahaving the plunger rod partially axially advanced.

FIG. 10C is a perspective view of the syringe assembly of FIG. 10Ahaving the plunger rod fully extended.

FIG. 10D is a perspective view of the syringe assembly of FIG. 10A inthe ready-to-use position.

FIG. 10E is a perspective view of the syringe assembly of FIG. 10Ahaving the plunger rod partially deployed to expel contents of thesyringe barrel.

DESCRIPTION OF PREFERRED EMBODIMENTS

For purposes of the description hereinafter, spatial orientation terms,if used, shall relate to the referenced embodiment as it is oriented inthe accompanying drawing figures or otherwise described in the followingdetailed description. However, it is to be understood that theembodiments described hereinafter may assume many alternative variationsand embodiments. It is also to be understood that the specific devicesillustrated in the accompanying drawing figures and described herein aresimply exemplary and should not be considered as limiting.

Referring to FIG. 1, a syringe assembly 10 according to an embodiment ofthe present invention is shown. The syringe assembly 10 includes asyringe barrel 20 and a plunger assembly 30. As shown in FIG. 1, thesyringe barrel 20 has an open proximal end 23 and a distal end 25opposite to the open proximal end 23. The syringe barrel 20 has aninside surface 21, which defines a chamber 22. As shown, the syringebarrel 20 may have a cylindrical or substantially cylindrical shape,though it is to be appreciated that the syringe barrel 20 may be formedin any suitable shape. Additionally, the syringe barrel 20 may be formedof glass, or may be injection molded from thermoplastic material such aspolypropylene and polyethylene according to techniques known to those ofordinary skill in the art, though it is to be appreciated that thesyringe barrel 20 may be made from other suitable materials andaccording to other applicable techniques.

The syringe barrel 20 also includes a substantially conical outlet tip26 disposed on the distal end 25 of the syringe barrel 20 in the form ofa conventional luer fitting. The outlet tip 26 is in fluid communicationwith the chamber 22 of the syringe barrel 20. A needle cannula (notshown) may be attached to the outlet tip 26 such that an interior of theneedle cannula is in fluid communication with the chamber 22 of thesyringe barrel 20. The needle cannula may be secured within the outlettip 26 by a chemical adhesive, such as epoxy, or may be mechanicallyaffixed to the outlet tip 26 according to known techniques.Alternatively, syringe assembly 10 is contemplated for use in connectionwith a separate needle assembly (not shown) such as through a standardluer slip fitting or luer lock fitting type connection with syringeassembly 10 at the outlet tip 26, or alternatively to a separateintravenous (IV) connection assembly (not shown). As such, a threadedluer collar 29 may further be provided for threaded engagement with sucha separate mechanism, as is known in the art.

The syringe assembly 10 may also include a protective cap (not shown)disposed over the outlet tip 26 to protect the needle cannula prior touse and to prevent accidental needle sticks of persons handling thesyringe assembly 10 prior to use. An annular ridge (not shown) may beformed on the distal end 25 of the syringe barrel 20 to facilitateattachment of a protective cap or a standard needle hub over the outlettip 26. An outwardly extending flange 24 may also be provided at theproximal end 23 of the syringe barrel 20 to assist in handling of thesyringe assembly 10. The outwardly extending flange 24 may have a pairof opposing apertures 27 extending through the flange 24.

With further reference to FIG. 1, the syringe assembly 10 also includesa plunger assembly 30 disposed at least partially within the syringebarrel 20. The plunger assembly 30 includes a flexible, elongatedplunger rod 31 that is slidably disposed on the syringe barrel 20. Theplunger rod 31 includes a handle portion 32 at the proximal end of theplunger rod 31 and a pair of flexible legs 33 extending distally fromthe handle portion 32. The flexible legs 33 each have a hook 34 formedat their distal ends. The plunger assembly 30 also includes a plungerhead in the form of stopper 40 disposed within the chamber 22 of thesyringe barrel 20. The stopper 40 includes a proximal surface 41, adistal surface 42, and a peripheral surface 43 extending between theproximal 41 and distal 42 surfaces. The peripheral surface 43 of thestopper 40 includes one or more sealing surfaces such as an annular ribso that the stopper 40 sealingly engages the inside surface 21 of thesyringe barrel 20 so as to seal the chamber 22.

A stopper adapter 35 is formed as an at least partially hollowcylindrical member having a sidewall 37 extending between a proximal end38 and a distal end 39. The distal end 39 of the stopper adapter 35 isattached to the proximal surface 41 of the stopper 40. A pair of slots36 is formed in the sidewall 37 of the stopper adapter 35 so that theflexible legs 33 of the plunger rod 31 may pass through the stopperadapter 35 from the proximal end 38 of the stopper adapter 35 andthrough the sidewall 37 via the slots 36 during use in an injectioncycle, as will be described in further detail herein.

In the initial position illustrated in FIG. 1, the plunger rod 31 is ina collapsed position with the flexible legs 33 extending through theslots 36 in the sidewall 37 of the stopper adapter 35 as well as theapertures 27 in the outwardly extending flange 24 and alongside andadjacent to the exterior surface 28 of the syringe barrel 20 to wrapover or around the exterior surface 28 of the syringe barrel 20 with thehandle portion 32 of the plunger rod 31 positioned proximate to theproximal end 23 of the syringe barrel 20, which minimizes the overalllength of the syringe assembly 10.

It is to be appreciated that the syringe assembly 10 according to thepresent embodiment is particularly suitable for use as a pre-filledsyringe with the stopper 40 provided at the proximal end 23 of thesyringe barrel 20. Alternatively, the plunger rod 31 could be used topull the stopper 40 proximally so as to aspirate an empty syringe barrel20. Syringe assembly 10 may be further provided with a mechanism so asto prevent re-use of the device. For example, the engagement betweenplunger rod 31 and stopper 40 as provided through flexible legs 33 andstopper adapter 35 may be a one-way engagement, in that flexible legs 33lock into stopper adapter 35 prior to the injection cycle, but once theinjection cycle is complete, any attempt to retract the plunger rod inthe opposite direction will cause the attachment between flexible legs33 and stopper adapter 35 to detach or otherwise break or shear, therebypreventing re-use of the device.

It is also to be appreciated that the syringe assembly 10 according tothe present embodiment allows for the overall length and width of apre-filled syringe to be minimized for packaging and storage savings andto reduce storage space in medicine drawers. For instance, the syringeassembly 10 according to the present embodiment achieves approximately70% reduction in length in the packaged pre-filled syringe.

With reference to FIGS. 2 and 3, a syringe assembly 100 according to afurther embodiment of the present invention is shown. The syringeassembly 100 operates in a manner similar to the syringe assembly 10discussed above with reference to FIG. 1 and as will be further detailedbelow with reference to FIGS. 5A-5F. The syringe assembly 100 includes asyringe barrel 110 and a plunger assembly 130. As shown in FIG. 2, thesyringe barrel 110 has an open proximal end 113 and a distal end 115opposite to the open proximal end 113. The syringe barrel 110 has anexterior surface 117 extending between the proximal 113 and distal 115ends and an inside surface 111, which defines a chamber 112. The syringebarrel 110 also includes an outlet 116 disposed on the distal end 115 ofthe syringe barrel 110. The outlet 116 is in fluid communication withthe chamber 112 of the syringe barrel 110.

As shown in FIGS. 2 and 3, the exterior surface 117 of the syringebarrel 110 is formed with a recessed grip region 120 that assists inholding the syringe assembly 100. Typical outwardly extending syringeflanges used to provide a gripping area for a syringe assembly areobtrusive and cause inefficiencies in storage due to their wide shape.By recessing a grip region 120 into the syringe barrel 110, there willbe no need for an outwardly extending flange. An exterior surface 121 ofthe recessed grip region 120 may be over-molded to provide a bettergripping surface or may include gripping dimples 122.

With further reference to FIGS. 2 and 3, a plunger assembly 130 includesa flexible, elongated plunger rod 131. The plunger rod 131 includes ahandle portion 132 at the proximal end of the plunger rod 131 and one ormore of flexible legs 133 extending distally from the handle portion132. While the embodiment is shown with a pair of flexible legs 133, itis contemplated that any number of flexible legs 133 can be provided.For example, in certain embodiments, the use of three flexible legs mayprovide an appropriate balanced bending moment of inertia for any axisof bending. The flexible legs 133 each have a hook 134 formed at theirdistal ends. The plunger assembly 130 also includes a stopper 140disposed within the chamber of the inner syringe barrel 110. The stopper140 includes a proximal surface 141, a distal surface 142, and aperipheral surface 143 extending between the proximal 141 and distal 142surfaces. The peripheral surface 143 of the stopper 140 includes one ormore sealing surfaces so that the stopper 140 sealingly engages theinside surface 111 of the syringe barrel 110 to seal the chamber 112 ofthe syringe barrel 110.

The flexible legs 133 extend through slots 118 in the syringe barrel 110proximate to the proximal end 113 of the syringe barrel 110 andalongside and adjacent to the exterior surface 117 of the syringe barrel110 to wrap over or around the exterior surface 117 of the syringebarrel 110 with the handle portion 132 of the plunger rod 131 positionedproximate to the proximal end 113 of the syringe barrel 110, whichminimizes the overall length of the syringe assembly 100. When it istime to use the syringe assembly 100, a user can pull the plunger rod131 proximally to an extended position. An inwardly extending proximalstop 114 is provided at the proximal end 113 of the syringe barrel 110to engage the hooks 134 at the ends of the flexible legs 133 and preventremoval of the plunger rod 131 from the syringe barrel 110.

Once the flexible legs 133 are withdrawn from the exterior surface 117of the syringe barrel 110, the plunger rod 131 is pushed forward so thatthe legs 133 mate with the proximal surface 141 of the stopper 140 toconnect the plunger rod 131 with the stopper 140 such that the plungerrod 131 can actuate the stopper 140 through an injection cycle. To thatend, the stopper 140 may be provided with a stopper adapter 135extending from the proximal surface 141 of the stopper 140 to facilitatethe engagement between the plunger rod 131 and the stopper 140 as ismore clearly shown in FIGS. 5A-5F. The stopper adapter 135 is similar tothe stopper adapter 35 discussed above with reference to FIG. 1.

Use of the device according to the embodiment of FIGS. 2 and 3 will bedescribed in connection with FIGS. 5A-5F, with continuing reference tothe features of FIGS. 2 and 3. Initially, the plunger rod 131 is in acollapsed position, as shown in FIG. 5A, with the flexible legs 133extending through the stopper adapter 135 and the slots 118 in thesyringe barrel 110 and alongside and adjacent to the exterior surface117 of the syringe barrel 110 to wrap over or around the exteriorsurface 117 of the syringe barrel 110 with the handle portion 132 of theplunger rod 131 positioned proximate to the proximal end 113 of thesyringe barrel 110, which minimizes the overall length of the syringeassembly 100.

When it is time to use the syringe assembly 100, a user can pull theplunger rod 131 proximally in the direction of arrow A as shown in FIG.5B, toward proximal end 113. During such movement, flexible legs 133travel through slots 118 near the proximal end 113 of syringe barrel100, to an extended position as shown in FIG. 5C in which the plungerrod 131 is in a fully retracted state. At this point with plunger rod131 in an extended position, flexible legs 133 are adapted to be lockedinto engagement with the stopper adapter 135. This may be accomplishedwith flexible legs 133 flexing inward as shown at arrows B in FIG. 5C.Such engagement may be automatic, with flexible legs 133 biased in adirection of arrows B, or alternatively, may require a user to pressradially against flexible legs 133 in the direction of arrows B.

In any event, such flexing of flexible legs 133 causes the hooks 134 atthe ends of the flexible legs 133 to lock into engagement with thestopper adapter 135, as shown in FIG. 5D, such that the stopper adapter135 and the stopper 140 may be pushed (and pulled) via the plunger rod131. With the plunger rod 131 in an extended position engaging thestopper 140 via the stopper adapter 135, the user may then push distallyon the plunger rod 131 in a direction of arrow C in FIG. 5E, therebycausing stopper 140 to move linearly axially within the chamber 112 ofthe syringe barrel 110 through an injection cycle to inject the contentsof the syringe barrel 110, as shown in FIG. 5E. At the end of theinjection cycle, stopper 140 is bottomed out within syringe barrel 110.Syringe assembly 100 can thereafter be properly discarded in anappropriate sharps disposal container.

With reference to FIG. 4, another embodiment of a syringe assemblyaccording to the present invention is shown. The syringe assemblyincludes an inner glass syringe barrel 150 having an outwardly extendingflange 151 at a proximal end thereof. In order to provide for a glasssyringe assembly having a more compact width, an outer plastic tube 160having a recessed, inverted flange 161 is disposed over the syringebarrel 150 such that the interior surface of the inverted flange 161engages the outwardly extending flange 151 of the syringe barrel 150 toretain the outer plastic tube 160 on the syringe barrel 150. Theexterior surface of the inverted flange 161 acts to provide a grippingarea for the syringe assembly in a similar manner to the recessed griparea 120 of the syringe barrel 110 illustrated in FIG. 2.

It is further contemplated that syringe assembly 10, 100 may be providedas an integrated product without the need for any external packaging tomaintain sterility. In such an embodiment, it is contemplated that a tipcap (not shown) can be provided at the distal end of syringe barrel 20,110, such as a cap fully surrounding and encompassing the outlet tip 26,and any luer collar or other fitting extending about the distal end 25,115. Such a tip cap provides for sterility of the contents of syringebarrel 20, 110 as well as the tip thereof. Moreover, proximal end 23,113 of syringe barrel 20, 110 may also be sealed to provide forsterility, such as through a removable or breakable membrane.

In one embodiment, it is contemplated that handle 32, 132 at theproximal end of plunger rod 31, 131 may be in sealing contact with theproximal end 23, 113 of syringe barrel 20, 110, such as at flange 24.Such sealing contact may be a breakable contact, which maintainssterility until a seal is actively broken by a user. In this manner,with a tip cap on the front end and such a seal at the rear end, syringeassembly 10, 100 can be provided as a fully packaged product requiringno additional outer packaging.

With such an arrangement, the overall size and shape of syringe assembly10, 100 when filled for use is of an overall profile similar to aconventional syringe after use with a plunger completely extended withina syringe barrel, as seen in FIG. 6, which depicts the profile of aconventional syringe 1 in comparison to syringe assembly 100 inaccordance with the present invention. As such, the profile issignificantly reduced from that of a conventional pre-filled syringe,which includes the plunger retracted from the barrel prior to use.

Reference is now made to FIGS. 7-9C, which show a syringe assemblyaccording to a further embodiment of the present invention, generallyindicated as 210, having a collapsed plunger rod, generally indicated as212, according to the present invention. The syringe barrel 214 has aproximal end 216, a distal end 218, and a sidewall 220 extending betweenthe proximal end 216 and the distal end 218. A stopper 222 is locatedwithin the syringe barrel 214 and a stopper adapter 224 is associatedwith the stopper 222. The stopper adapter 224 may be integrally formedwith the stopper 222 or may be a separately molded member having a firstend secured to the stopper 222. The syringe barrel 214, stopper 222, andstopper adapter 224 define a longitudinal axis L, as shown in FIG. 7.The plunger rod 212 may be secured to the stopper adapter 224 and isconfigured for cooperation with the stopper adapter 224 to move from acollapsed pre-use position to an expanded ready-to-use position.

In one embodiment, the plunger rod 212 is adapted to transition from thepre-use position in which the plunger rod 212 extends substantiallyparallel with and alongside and adjacent to the sidewall 220 of thesyringe barrel 214, to the expanded ready-to-use position in which theplunger rod 212 extends substantially in line with the longitudinal axisof the syringe barrel 214, stopper 222, and the stopper adapter 224. Inone embodiment, the plunger rod 212 includes a first end 228 and asecond end 230 with an attachment member 232 disposed adjacent thesecond end 230. The stopper adapter 224 may include a joining end 226configured for connection with the attachment member 232 of the plungerrod 212 in the ready-to-use position.

According to one design, a containing member 236 may be providedadjacent a cut-out portion 246 or recessed groove in the proximal end216 of the syringe barrel sidewall 220, which is dimensioned to allow aportion of the plunger rod 212 to pass therethrough. The cut-out portion246 may also be dimensioned such that the first end 228 and the secondend 230 may not pass through the cut-out portion 246 and are restrainedby the containing member 236 preventing inadvertent separation of theplunger rod 212 from the syringe assembly 210 in the initial pre-useposition or during transition of the plunger rod 212 to the ready-to-useposition.

Outward or pivotal movement by a clinician in the direction of arrowshown in FIG. 7 can dislodge the plunger rod 212 from the syringe barrelsidewall 220 and dislodge the plunger rod 212 from the joining end 226of the stopper adapter 224 for activation of the plunger rod 212 to theexpanded ready-to-use state. During transition of the syringe assembly210 from the initial position to the ready-to-use position, the plungerrod 212 is advanced in an angled substantially proximal direction asshown by arrow E of FIG. 8A.

Reference is now made to FIGS. 8A-8C which shows sequential perspectiveviews of the movement of the collapsed plunger rod 212 into theready-to-use position. In operation, the plunger rod 212 moves from thecollapsed position to the expanded position through a pivoting motion ofthe second end 230 of the plunger rod 212, as shown in FIG. 8A, in aradial direction with respect to the syringe barrel 214. A subsequentapplication of a force to the plunger rod 212 in the proximal direction,as shown by arrow E of FIG. 8A causes the plunger rod 212 to slide in anaxial direction toward the proximal end 216 of the syringe barrel 214.

The syringe assembly 210 can further include a flange 240 located at theproximal end 216 of the syringe barrel 214. This flange 240 can includean opening 242 which is in alignment with an opening 244 in the stopperadapter 224 through which the plunger rod 212 extends. The cut-outportion 246 can be provided in the proximal end 216 of the syringebarrel sidewall 220 to facilitate movement of the attachment member 232through the flange opening 242 and the stopper adapter opening 244.Openings 242, 244 and cut-out portion 246 are best shown in FIG. 8B.

The applied axial movement causes the plunger rod 212 to move throughthe openings in the flange 242 and the stopper adapter 244 to align theplunger rod 212 along the longitudinal axis of the syringe barrel 214,stopper 222, and stopper adapter 224. The attachment member 232 on theplunger rod 212 then snaps into the joining end 226 of the stopperadapter 224 to secure the plunger rod 212 thereto in the expandedready-to-use position. The attachment member 232 can include at leastone detent bump 234, shown in FIG. 7, which flexes the plunger rod 212outward when pulled. The attachment member 232 joined with a receivingmember 248 located in the stopper adapter 224 is clearly shown in FIGS.8B and 8D. FIG. 8D is a partial front cross-sectional view of thesyringe assembly 210 having the plunger rod 212 in the ready-to-useposition. For purposes of clarity, the plunger rod 212 is notillustrated in cross-section.

Optionally, the plunger rod 212 can include a thumb press member 250located at the first end 228 thereof. Preferably, this thumb pressmember 250 is located above the proximal end 216 of the syringe barrel214 and the flange 240. The plunger rod 212 can include an inwardlycurved portion 252 to facilitate manipulation of the plunger rod 212through the openings 242, 244 and the cut-out portion 246 of the syringebarrel 214.

The application of force to plunger rod 212 can be applied by a pushingmotion to the plunger rod 212 or to the second end 230 of the plungerrod 212 and/or by applying a pulling motion to the thumb press member250. The transition from the partially expanded position of FIG. 8B tothe fully expanded position of FIGS. 8C-8D requires the plunger rod 212to be slightly moved in a radial direction with respect to the stopperadapter 224 and stopper 222 to snap the attachment member 232 into thereceiving member 248 of the stopper adapter 224 so that the plunger rod212 is axially aligned with the longitudinal axis of the syringe barrel214, stopper adapter 224, and stopper 222, placing the syringe assembly210 in the ready-to-use position. The syringe assembly 210 is shown inFIGS. 9A-9C in the ready-to-use position having the plunger rod 212fully extended and engaged with the stopper adapter 224. FIG. 9A is afront cross-sectional view of the syringe assembly 210 having theplunger rod 212 in the ready-to-use position. For purposes of clarity,the plunger rod 212 is not illustrated in cross-section.

Referring to FIGS. 10A-10E, the usage of a syringe assembly 310 having acollapsible plunger rod 312, according to another embodiment of thepresent invention similar to the embodiment discussed above withreference to FIGS. 7-9C, is demonstrated. As shown, the plunger rod 312may further include a magnification member 362. The syringe assembly 310is shown in its initial unused position in FIG. 10A. The plunger rod 312may have a magnification member 362 disposed over indicia disposed on orwith the syringe barrel sidewall 320, allowing a medical practitioner toeasily identify the contents and dosing of the syringe assembly 310prior to use.

As shown in FIG. 10B, the plunger rod 312 may be pulled axially alongthe longitudinal axis L₂ of the syringe assembly 310 toward the proximalend 316 of the syringe barrel 314 and through cut-out portion 346. Thefully extended plunger rod 312 is shown in FIG. 10C, having theattachment member 332 restrained by the containing member 337 to preventseparation of the plunger rod 312 from the syringe assembly 310. Asshown in FIG. 10D, the attachment member 332 is engaged with the secondend 326 of a stopper adapter to secure the plunger rod 312 with thestopper 322. As shown in FIG. 10E, the plunger rod 312 may be thendeployed to expel the contents of the syringe barrel 314 by providing anaxial force in the direction shown by arrow F to the thumb press member350.

It can be appreciated that the collapsible plunger rod of the inventionlocks in place during use and can then be unlocked or unassembled to itsinitial position after use, where the plunger rod extends substantiallyparallel with and alongside and adjacent to the syringe body, to reducethe length of the syringe assembly to allow for sharps disposal. The useof the syringe assembly 310 having a collapsed plunger rod 312 of theinvention can result in up to approximately a 70% reduction in length ofthe packaged syringe product.

While several embodiments of a syringe assembly that has a collapsibleplunger rod were described in the foregoing detailed description, thoseskilled in the art may make modifications and alterations to theseembodiments without departing from the scope and spirit of theinvention. Accordingly, the foregoing description is intended to beillustrative rather than restrictive. The invention describedhereinabove is defined by the appended claims and all changes to theinvention that fall within the meaning and the range of equivalency ofthe claims are embraced within their scope.

The invention claimed is:
 1. A method of actuating a syringe assembly,comprising the steps of: providing the syringe assembly, comprising: asyringe barrel having an exterior surface, an inside surface defining achamber, an open proximal end, a distal end, and an outlet disposedadjacent the distal end in fluid communication with the chamber; and aplunger assembly disposed at least partially within the syringe barrel,the plunger assembly including a plunger head and an elongated plungerrod having a first end and a second end, the elongated plunger rod beingassociated with the plunger head to move the plunger head within thechamber of the syringe barrel through an injection cycle, wherein thesyringe barrel further includes at least one slot defined in theexterior surface between the open proximal end and the distal end andthe plunger rod extends through the at least one slot and alongside atleast a portion of the exterior surface of the syringe barrel in acollapsed position, said plunger rod being adapted to slidably move withrespect to the syringe barrel; slidably withdrawing the plunger rod fromthe collapsed position to an extended position wherein at least aportion of the plunger rod remains in contact with the syringe assemblyduring transition from the collapsed position to the extended position;engaging the second end of the plunger rod with the plunger head to lockthe plunger rod into engagement with the plunger head; and advancing theplunger assembly within the chamber of the syringe barrel so that theplunger head slides within the chamber with respect to the syringebarrel in a distal direction.
 2. The method of claim 1, wherein thesyringe barrel further includes an outwardly extending flange disposedat the open proximal end of the syringe barrel and at least one openingextending through the flange and wherein the plunger rod extends throughthe at least one opening.
 3. The method of claim 1, wherein the plungerrod extends substantially parallel with the exterior surface of thesyringe barrel in the collapsed position and extends substantially inline with a longitudinal axis of the syringe barrel in the extendedposition.
 4. The method of claim 1, wherein the plunger rod includes anattachment member located at the second end.
 5. The method of claim 4,wherein the attachment member on the plunger rod secures the plunger rodto the plunger head in the extended position.
 6. The method of claim 1,wherein the plunger head includes a stopper having a proximal surface, adistal surface, and a peripheral surface extending between the proximalsurface and the distal surface, the peripheral surface including atleast one sealing surface for sealingly engaging the inside surface ofthe syringe barrel.
 7. The method of claim 6, wherein the plunger headfurther includes a stopper adapter disposed on the proximal surface ofthe stopper, the stopper adapter being adapted to engage the plunger rodduring the injection cycle.
 8. The method of claim 7, further includinga flange located at the proximal end of the syringe barrel, the flangeincluding an opening in alignment with an opening in the stopper adapterthrough which the plunger rod extends wherein movement of the plungerrod from the collapsed position to the extended position includespivoting the second end of the plunger rod in a radial direction withrespect to the syringe barrel and then applying a proximal force to theplunger rod to axially slide the plunger rod through the openings in theflange and the stopper adapter and secure the second end of the plungerrod with the stopper adapter.
 9. The method of claim 1, furtherincluding a cut-out portion in the proximal end of the syringe barreland a containing member positioned adjacent the cut-out portion whereinsaid cut-out portion and said containing member are dimensioned to allowa portion of the plunger rod to pass therethrough but are dimensioned toprevent the first end and the second end of the plunger rod from passingthrough the cut-out portion to prevent inadvertent separation of theplunger rod from the plunger assembly.
 10. The method of claim 1,wherein the plunger rod further includes an inwardly curved portion tofacilitate manipulation of the plunger rod during transition from thecollapsed position to the extended position.
 11. The method of claim 1,wherein the plunger rod includes a thumb press member located at thefirst end of the plunger rod and located above the proximal end of thesyringe barrel.
 12. A method of actuating a syringe assembly, comprisingthe steps of: providing the syringe assembly, comprising: a syringebarrel having an exterior surface, an inside surface defining a chamber,an open proximal end, a distal end, and an outlet disposed adjacent thedistal end in fluid communication with the chamber; and a plungerassembly disposed at least partially within the syringe barrel, theplunger assembly including a plunger head and an elongated plunger rodhaving a first end and a second end, the elongated plunger rod beingassociated with the plunger head to move the plunger head within thechamber of the syringe barrel through an injection cycle, wherein thesyringe barrel further includes at least one slot defined in theexterior surface and the plunger rod extends through the at least oneslot and alongside the exterior surface of the syringe barrel in acollapsed position, said plunger rod being adapted to slidably move withrespect to the syringe barrel; slidably withdrawing the plunger rod fromthe collapsed position to an extended position wherein at least aportion of the plunger rod remains in contact with the syringe assemblyduring transition from the collapsed position to the extended position;engaging the second end of the plunger rod with the plunger head to lockthe plunger rod into engagement with the plunger head; and advancing theplunger assembly within the chamber of the syringe barrel so that theplunger head slides within the chamber with respect to the syringebarrel in a distal direction, wherein the plunger head includes astopper having a proximal surface, a distal surface, and a peripheralsurface extending between the proximal surface and the distal surface,the peripheral surface including at least one sealing surface forsealingly engaging the inside surface of the syringe barrel, wherein theplunger head further includes a stopper adapter disposed on the proximalsurface of the stopper, the stopper adapter being adapted to engage theplunger rod during the injection cycle, and wherein the syringe barrelfurther includes a flange located at the proximal end of the syringebarrel, the flange including an opening in alignment with an opening inthe stopper adapter through which the plunger rod extends whereinmovement of the plunger rod from the collapsed position to the extendedposition includes pivoting the second end of the plunger rod in a radialdirection with respect to the syringe barrel and then applying aproximal force to the plunger rod to axially slide the plunger rodthrough the openings in the flange and the stopper adapter and securethe second end of the plunger rod with the stopper adapter.